Cerebral Hemodynamic Parameters Research Articles

Brain Perfusion and Hemodynamic Changes in Moyamoya Disease

Moyamoya disease (MMD) – is a chronic progressive disorder of the unknown etiology with the development of the critical stenoses in internal carotid arteries and abnormal vascular net formation at the basal cerebrum to compensate the hemodynamic insufficiency and further development of the ischemic attacks, strokes, hematomas. The objective: to study the cerebral hemodynamic parameters and brain perfusion in patients with moyamoya disease. Materials and methods. We performed retrospective analysis of the cerebral angiography and cerebral perfusion investigations results of 6 patients with moyamoya desease, who were hospitalized in the State Institution «Romodanov Neurosurgery Institute of NAMS of Ukraine» in 2016–2020. All patients underwent a comprehensive examination, which included neuropsychological testing, the head and neck vessels duplex scanning, multispiral computed tomography (MSCT), selective cerebral angiography (SCA), and MSCT-angiography. The assessment of myamoya vessels was done by the Suzuki angiographic scale. Cerebral hemodynamics was studied by perfusion MSCT (PMSCT). Results. The diagnosis of moyamoya desease was confirmed in all patients by SCA and MSCT angiography. The clinical manifestation of the disease was represented by ischemic (n=5; 83.3%) and hemorrhagic (n=1; 16.7%) strokes. Stage 3, Stage 4 and Stage 6 has been diagnosed by Suzuki angiographic scale. Changes of the cerebral perfusion were more significant at Stage 4 / Stage 6: CBV was increased up to 20%, CBF was decreased > 30% with MTT time > 6 sec. The most significant changes were founed ipsilaterally in the territories of the MCA, moderate – in the territories of the ACA and PCA. Conclusion. In patients with moyamoya disease we have found the restructuring of the cerebral angioarchitectonics which has been matching the decrease of cerebral perfusion. Perfusion MSCT allows to get identification of the areas with an increased risk of ischemia and provides a decisive quantitative assessment of cerebral hemodynamics changes to establish indications for surgical treatment.

Assessment of cerebral circulation through an intact skull using imaging photoplethysmography

The feasibility of assessing the parameters of cerebral hemodynamics without skull trepanation using imaging photoplethysmography with illumination in the near-infrared spectrum range was demonstrated for the first time. The results were obtained when studying changes in blood flow in the rat brain in response to short-term respiratory failure (apnea test). Translation of the results into clinical practice will be useful for the development of a method for non-invasive assessment of cerebral blood flow in patients with cerebrovascular diseases.

Destructive hypoxic-ischemic brain injury in full-term infants with normothermia and hypothermia

Background. Despite the achievements of neonatology, severe asphyxia at birth and hypoxic-ischemic encephalopathy in full-term infants are still associated with high lethality, long-term neurological morbidity and disability. In the algorithm for the ma­nagement of children with hypoxic-ischemic encephalopathy, it is important to use methods of additional examinations, including ultrasound examination of the brain (neurosonography), its potential for the early evaluation of the severity of the brain tissue injury using therapeutic hypothermia. Thus, the aim of the research was to determine the effect of therapeutic hypothermia on the severity of neurosonographic signs of destructive hypoxic-ischemic brain injury in full-term newborns. Materials and methods. Data were analyzed for 50 full-term neonates with severe asphyxiation and signs of destructive hypoxic-ischemic brain injury. The first group (hypothermia group 1) included 12 newborn infants who were treated with hypothermia in 2014–2016. The second group (hypothermia group 2) — 14 children with severe asphyxiation who were treated with hypothermia in 2011–2013. The third group (group of normothermia) consisted of 24 full-term babies born in 2009–2010, with no therapeutic hypothermia. Results. The share of the most severe destructive brain injuries (diffuse ischemic lesions) was 33.3 % in the first group, 35.7 % in the second group and 45.8 % in the third group. Significant differences between groups in terms of the frequency of diffuse ischemic brain injures were not found. In general, in the structure of destructive hypoxic-ischemic brain injuries in newborns after hypothermia, diffuse ischemic lesions were detected in 34.6 % of cases (non-significant differences with the group of normothermia, p = 0.385 according to Fisher’s criterion calculations). When studying the indicators of cerebral blood flow, reliable differences were found for the index of resistance of the anterior cerebral artery on the third day of life (0.53 ± 0.05 for normothermia group and 0.65 ± 0.04 for hypothermia group). Conclusions. Despite the reduction in the proportion of the most severe diffuse ischemic brain injuries among the total number of diagnosed destructive hypoxic-ischemic lesions during the introduction of hypothermia, the statistical analysis did not reveal any significant differences between the groups. After all, the development of diffuse ischemic brain injuries, first of all, is due to primary asphyxia lesions that lead to global deaths of neurons, or by these injuries, the phase of the therapeutic window in which ended up at the time of birth. But significant differences in the parameters of cerebral hemodynamics prove the fact that the potential of therapeutic hypothermia for the prevention of secondary reperfusion injury remains in these cases.

Effect of a temporary lying position on cerebral hemodynamic and cerebral oxygenation parameters in patients with severe brain trauma.

Temporary transition from the half-seated position (HSP) to the lying position (LyP) is often associated with an increase in intracranial pressure (ICP) during management of patients with severe traumatic brain injury (TBI). This study was designed to assess the impact of the temporary LyP on cerebral perfusion and oxygenation in cases of severe TBI. Patients with a severe blunt TBI with indication of ICP monitoring were prospectively included. Patients underwent standardized management according to the international guidelines to minimize secondary insults. For each patient, a maneuver to a LyP for 30min was performed daily during the first 7days of hospitalization. ICP, cerebral perfusion pressure (CPP), mean velocity (Vm), pulsatility index (PI), regional cerebral oxygen saturation (rScO2), jugular venous oxygen saturation (SvjO2)) were compared in the HSP and the LyP. Twenty-four 24 patients were included. The median Glasgow coma scale score was 6 (interquartile range (IQR), 3-8), the median injury severity score was 32 (IQR, 25-48), and the mean age was 39 ± 16years. On day 1, ICP (+ 6mmHg (IQR, 4-7mmHg)) and CPP (+ 10mmHg (IQR, 5-14mmHg) were significantly increased in the LyP compared with the HSP. Vm increased significantly in the LyP on the mainly injured side (+ 6cm/s (IQR, + 0-11cm/s); P = 0.01) and on the less injured side (+ 4cm/s (IQR, + 1-8cm/s); P < 0.01). rScO2 behaved similarly (+ 2 points (IQR, + 2-4 points) and + 3 points (IQR, + 2-5 points), respectively; P < 0.001). Mixed models highlighted the significant association between the position and CPP, Vm, rScO2, with more favorable conditions in the lying position. Within the first week of management, the temporary LyP in cases of severe TBI was associated with a moderate increase in CPP, Vm, and rScO2despite a moderate increase in ICP.

Multi-Parametric Evaluation of Cerebral Hemodynamics in Neonatal Piglets Using Non-Contrast-Enhanced Magnetic Resonance Imaging Methods.

Disruption of brain oxygen delivery and consumption after hypoxic-ischemic injury contributes to neonatal mortality and neurological impairment. Measuring cerebral hemodynamic parameters, including cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2 ), is clinically important. Phase-contrast (PC), velocity-selective arterial spin labeling (VSASL), and T2 -relaxation-under-phase-contrast (TRUPC) are magnetic resonance imaging (MRI) techniques that have shown promising results in assessing cerebral hemodynamics in humans. We aimed to test their feasibility in quantifying CBF, OEF, and CMRO2 in piglets. Prospective. Ten neonatal piglets subacutely recovered from global hypoxia-ischemia (N=2), excitotoxic brain injury (N=6), or sham procedure (N=2). VSASL, TRUPC, and PC MRI acquired at 3.0 T. Regional CBF was measured by VSASL. Global CBF was quantified by both PC and VSASL. TRUPC assessed OEF at the superior sagittal sinus (SSS) and internal cerebral veins (ICVs). CMRO2 was calculated from global CBF and SSS-derived OEF. End-tidal carbon dioxide (EtCO2 ) levels of the piglets were also measured. Brain damage was assessed in tissue sections postmortem by counting damaged neurons. Spearman correlations were performed to evaluate associations among CBF (by PC or VSASL), OEF, CMRO2 , EtCO2 , and the pathological neuron counts. Paired t-test was used to compare OEF at SSS with OEF at ICV. Global CBF was 32.1 ± 14.9 mL/100 g/minute and 30.9 ± 8.3 mL/100 g/minute for PC and VSASL, respectively, showing a significant correlation (r=0.82, P < 0.05). OEF was 54.9 ± 8.8% at SSS and 46.1 ± 5.6% at ICV, showing a significant difference (P < 0.05). Global CMRO2 was 79.1 ± 26.2 μmol/100 g/minute and 77.2 ± 12.2 μmol/100 g/minute using PC and VSASL-derived CBF, respectively. EtCO2 correlated positively with PC-based CBF (r=0.81, P < 0.05) but negatively with OEF at SSS (r=-0.84, P < 0.05). Relative CBF of subcortical brain regions and OEF at ICV did not significantly correlate, respectively, with the ratios of degenerating-to-total neurons (P=0.30, P=0.10). Non-contrast MRI can quantify cerebral hemodynamic parameters in normal and brain-injured neonatal piglets. 1 TECHNICAL EFFICACY STAGE: 2.

Cerebral Autoregulation in Ischemic Stroke: From Pathophysiology to Clinical Concepts.

Ischemic stroke (IS) is one of the most impacting diseases in the world. In the last decades, new therapies have been introduced to improve outcomes after IS, most of them aiming for recanalization of the occluded vessel. However, despite this advance, there are still a large number of patients that remain disabled. One interesting possible therapeutic approach would be interventions guided by cerebral hemodynamic parameters such as dynamic cerebral autoregulation (dCA). Supportive hemodynamic therapies aiming to optimize perfusion in the ischemic area could protect the brain and may even extend the therapeutic window for reperfusion therapies. However, the knowledge of how to implement these therapies in the complex pathophysiology of brain ischemia is challenging and still not fully understood. This comprehensive review will focus on the state of the art in this promising area with emphasis on the following aspects: (1) pathophysiology of CA in the ischemic process; (2) methodology used to evaluate CA in IS; (3) CA studies in IS patients; (4) potential non-reperfusion therapies for IS patients based on the CA concept; and (5) the impact of common IS-associated comorbidities and phenotype on CA status. The review also points to the gaps existing in the current research to be further explored in future trials.

Effect of delayed cord clamping and umbilical cord milking on cerebral hemodynamics in preterm infants: a randomized double-blind controlled trial

Objective To compare the effect of delayed cord clamping (DCC) versus umbilical cord milking (UCM) on cerebral blood flow in preterm infants. Methods This was a single-center, prospective, double-blind, randomized controlled trial. A total of 46 preterm infants, with a gestational age of 30-33+6 weeks, who were born in Suining Central Hospital from November 2, 2018 to November 15, 2019 were enrolled and randomly divided into DCC group and UCM group, with 23 infants in each group. The primary outcome indexes included cerebral hemodynamic parameters[peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI)] measured by ultrasound within 0.5-1 hour, (24±1) hours, (48±1) hours, and (72±1) hours after birth. Secondary outcome indexes included hematocrit, hemoglobin, red blood cell count, and serum total bilirubin levels on the first day after birth and the incidence rate of intraventricular hemorrhage during hospitalization. Results A total of 21 preterm infants in the DCC group and 23 in the UCM group were included in the statistical analysis. There was no significant difference in PSV, EDV, and RI between the two groups at all time points after birth (P > 0.05). There was also no significant difference between the two groups in the hematocrit, hemoglobin, red blood cell count and total bilirubin levels on the first day after birth, and the incidence rate of intraventricular hemorrhage during hospitalization (P > 0.05). Conclusions DCC and UCM have a similar effect on cerebral hemodynamics in preterm infants with a gestational age of 30-33+6 weeks.

Needle reflexology in the treatment of neurological changes in ischemic stroke

In recent years, the problem of diagnosis and preventive treatment of cerebrovascular diseases has become increasingly relevant. Stroke is the most common cause of permanent disability (E. I. Gusev, 2007). The leading role in the diagnosis and prognosis of stroke, as well as the choice of further treatment and rehabilitation tactics is assigned to non-invasive ultrasound research methods, which make it possible to assess the parameters of cerebral hemodynamics. (I. D. Stulin, 2006).

The Effects of Gradual Change in Head Positioning on the Relationship between Systemic and Cerebral Haemodynamic Parameters in Healthy Controls and Acute Ischaemic Stroke Patients.

(1) Background: Larger blood pressure variability (BPv) in the first 3 h post-stroke onset increases pathophysiological effects such as infarct size, and leads to greater risk of disability, comorbidities and mortality at 90 days. However, there is limited information on the relationship between systemic and cerebral haemodynamic and variability parameters. (2) Objectives: This study determined the effect of a gradual change in head position (GHP) on cerebral blood flow velocity variability (CBFVv) and mean arterial blood pressure variability (MABPv), in healthy controls and acute ischaemic stroke (AIS) patients. Methods: CBFVv and MABPv were expressed as standard deviation (SD) and coefficient of variation. A total of 16 healthy controls (mean age 57 ± 16 years) were assessed over two visits, 12 ± 8 days apart, and 15 AIS patients (mean age 69 ± 8.5 years) were assessed over three visits (V1: 13.3 ± 6.9 h, V2: 4.9 ± 3.2 days and V3: 93.9 ± 11.5 days post-stroke). (3) Results: In response to GHP, MABPv does not initially increase, but over time MABPv showed a significant increase in response to GHP in AIS (visits 2 and 3) and controls (visit 2). Additionally, in response to GHP in AIS, CBFVv increased in the affected hemisphere. Lastly, in AIS, a significant correlation between CBFVv and MABPv, assessed by SD, was seen in the unaffected hemisphere, whereas this relationship was not demonstrated in the affected hemisphere. (4) Conclusions: To our knowledge, this is the first study to analyse the relationship between CBFVv and MABPv. Shedding light on the effect of head position on the relationship between cerebral blood flow and blood pressure is important to improve our understanding of the underlying effects of cerebral autoregulation impairment. This early mechanistic study provides evidence supporting supine head positioning in healthy controls and stroke patients, through demonstration of a reduction of MABPv and increase in CBFVv.

Does depth of squat-stand maneuver affect estimates of dynamic cerebral autoregulation?

Repeated squat‐stand maneuvers (SSM) are an effective way of measuring dynamic cerebral autoregulation (dCA), but the depth of SSM required to improve dCA estimations has never been studied. We compared beat‐to‐beat cerebral hemodynamic parameters between maximal depth SSM (SSMD) and a shallower alternative (SSMS) in two age groups (younger [20–34 years] vs. older [50–71 years]) at a frequency of 0.05 Hz. Cerebral blood flow velocity, continuous blood pressure (BP) and end‐tidal CO2 (EtCO2) were measured using transcranial Doppler ultrasound, the Finometer device, and capnography, respectively. Coherence (at 0.05 Hz) was significantly higher in both SSM recordings compared to spontaneous BP oscillations at baseline standing (BS). Median (IQR) autoregulation index (ARI) was reduced during SSMD (4.46 [4.03–5.22], p < .01) compared to SSMS (5.96 [5.40–6.69]) and BS (6.03 [5.20–6.49], p < .01) with similar relative differences also observed for phase (at 0.05 Hz). End‐tidal CO2 was increased in SSMD (38.3 ± 3.7 mmHg, p < .01) compared to both SSMS (36.6 ± 3.6 mmHg) and BS (35.5 ± 3.2 mmHg). The older group demonstrated significantly lower ARI and phase estimates during SSM and found SSMS more effortful than SSMD. In conclusion, both SSMD and SSMS are effective at estimating dCA, and dCA appears to be less efficient during maximal depth SSM compared to baseline rest or a shallower alternative.

An Efficient Framework for Accurate Arterial Input Selection in DSC-MRI of Glioma Brain Tumors

Automatic and accurate arterial input function (AIF) selection has an essential role for quantification of cerebral perfusion hemodynamic parameters using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). The purpose of this study is to develop an optimal automatic method for arterial input function determination in DSC-MRI of glioma brain tumors by using a new preprocessing method.For this study, DSC-MR images of 43 patients with glioma brain tumors were retrieved retrospectively. Our proposed AIF selection framework consisted an effcient pre-processing step, through which non-arterial curves such as tumorous, tissue, noisy and partial-volume affected curves were excluded, followed by AIF selection through agglomerative hierarchical (AH) clustering method. The performance of automatic AIF clustering was compared with manual AIF selection performed by an experienced radiologist, based on curve shape parameters, i.e. maximum peak (MP), full-width-at-half-maximum (FWHM), M (=MP/ (TTP × FWHM)) and root mean square error (RMSE).Mean values of AIFs shape parameters were compared with those derived from manually selected AIFs by two-tailed paired t-test. The results showed statistically insignificant differences in MP, FWHM, and M parameters and lower RMSE, approving the resemblance of the selected AIF with the gold standard. The intraclass correlation coefficient and coefficients of variation percent showed a better agreement between manual AIF and our proposed AIF selection than previously proposed methods.The results of current work suggest that by using efficient preprocessing steps, the accuracy of automatic AIF selection could be improved and this method appears promising for efficient and accurate clinical applications.

Effect of acupuncture combined with repetitive transcranial magnetic stimulation on motor function and cerebral hemodynamics in children with spastic cerebral palsy with spleen-kidney deficiency

To investigate the clinical effect of acupuncture combined with repetitive transcranial magnetic stimulation in the treatment of children with spastic cerebral palsy with spleen-kidney deficiency, as well as its effect in improving cerebral hemodynamics. A total of 220 children with spastic cerebral palsy were divided into observation group and control group using a random number table, with 110 children in each group. The children in the control group were given rehabilitation training and repetitive transcranial magnetic stimulation, and those in the observation group were given acupuncture in addition to the treatment in the control group. Acupuncture was performed at Zusanli (ST36), Xuanzhong (GB39), Sanyinjiao (SP6), Pishu (BL20), Shenshu (BL23), Qihai (CV6), Quchi (LI11), Neiguan (PC6), Hegu (LI4) and Tianshu (ST25) once every other day, three times a week for 3 consecutive months. The two groups were compared in terms of Gross Motor Function Measure (GMFM), Fine Motor Function Measure (FMFM), comprehensive function score for children with cerebral palsy, clinical outcome, and related cerebral hemodynamic parameters (mean blood flow velocity [Vm], systolic peak velocity [Vs], and resistance index [RI] of the cerebral artery). After treatment, both groups had significant increases in the scores of GMFM, FMFM and comprehensive function (cognitive function, speech function, motor ability, self-care, and social adaptability,P<0.01), and the observation group had significantly better improvements in the scores of GMFM (domains A, B and C), FMFM (domains B, C, D and E), and comprehensive function than those of the control group (P<0.01). The therapeutic effect of the observation group (93/110, 84.55%)was superior to that of the control group (80/110, 72.73%, P<0.05). The observation group had significantly higher Vs and Vm and a significantly lower RI than the control group (P<0.01). In the treatment of children with spasmodic cerebral palsy with spleen-kidney deficiency, acupuncture combined with repeated transcranial magnetic stimulation can significantly improve their motor function, comprehensive function, and clinical outcome, which may be associated with the regulation of cerebral hemodynamics.

Effects of Tai Chi on Cerebral Hemodynamics and Health-Related Outcomes in Older Community Adults at Risk of Ischemic Stroke: A Randomized Controlled Trial.

This study investigated the effects of Tai Chi compared with no exercise control on the cerebral hemodynamic parameters and other health-related factors in community older adults at risk of ischemic stroke. A total of 170 eligible participants were randomly allocated to Tai Chi or control group. The cerebral hemodynamic parameters and physical fitness risk factors of cardiovascular disease were measured at baseline, 12 weeks, and 24 weeks. After the 12-week intervention, Tai Chi significantly improved the minimum of blood flow velocity (BFVmin); BFVmean; pulsatility index and resistance index of the right anterior cerebral artery; and BFVmax, BFVmin, and BFVmean parameters of the right middle cerebral artery. Tai Chi training also decreased triglyceride, fasting blood glucose, and homocysteine levels, and improved balance ability. Therefore, the supervised 12-week Tai Chi exercise had potential beneficial effects on cerebral hemodynamics, plasma risk factors, and balance ability in older community adults at risk of ischemic stroke.

P: 21 Changes in Cerebral Hemodynamic Parameters in Patients With Acute Liver Failure

BACKGROUND: Acute liver failure (ALF) is a clinical syndrome that results from severe and sudden loss of liver function in a patient without preexisting liver disease.1 High intracranial pressure (ICP) leads to loss of cerebral perfusion, brain herniation and irreversible brain damage in patients with acute liver failure (AHF).2 Transcranial Doppler ultrasound (TCD) is a non-invasive device that can continuously measure the speed of cerebral blood flow, producing a velocity-time waveform that indirectly monitors changes in cerebral hemodynamics, making it very useful in patients with ALF.3,4 Objetives Compare the cerebral hemodynamic parameters in patients with ALF using TCD before and after liver transplantation. METHODS: Retrospective and descriptive study. We searched patients with ALF during the period 2014–2018, who underwent TDC. For the descriptive analysis, medians of the quantitative variables and percentages of the qualitative variables were used. The comparison of medians was made using t student. Values were expressed as median and interquartile range, analyzed with Mann-Whitney U test. A value of P &lt; 0.05 was considered statistically significant. RESULTS: We studied 10 patients (9 women, 1 man), with a median age of 29 years. The etiology of the liver failure was the following: 50% for autoimmune hepatitis, 20% undetermined, 10% hepatitis A and 10% pharmacological. We identified 4 deaths, 1 of which was during the post-transplant period. The following parameters were measured: systolic peak velocity (SPV), final diastolic velocity (FDV), médium veloctiy of the middle brain artery (VM), resistance index (RI) and pulsatility index (PI). There was changes in RI and PI, before transplant TDC: RI 0.69 (0.58–0.71) PI 1.29 (0.96–1.37) and after transplant TDC RI 0.51 (0.0–0.58), PI 0.78 (0.55–0.95) P value = 0.005 and 0.005 respectively. CONCLUSIONS: There was a significant decrease in the rates of pulsatility and resistance after liver transplantation.

Transcranial Doppler ultrasound measurements of cerebral hemodynamic parameters in healthy volunteers at 2850 meters altitude

BackgroundTranscranial Doppler ultrasound (TDU) is useful in cerebrovascular patients. TDU findings are operator-dependent; they can also be influenced by anatomical and physiological variables as well as by the altitude at which the study is done. ObjectiveTo report the cerebral hemodynamic parameters measured by TDU in subjects who live in Quito, Ecuador (altitude 2850m). Material and methodsWe recruited 47 volunteers with no history or clinical evidence of stroke, hypertension, metabolic disorders, or hematologic disorders; 2 patients were excluded because they did not have a viable cranial window for TDU study. Thus, we recorded mean cerebral blood flow velocity, peak systolic flow velocity, end-diastolic flow velocity, and pulsatility indices in 45 patients (28 (62.2%) women; mean age, 35.9 years). We recorded patients’ age, sex, and hematocrit. We analysed cerebrovascular hemodynamic parameters by sex and age group. ResultsNo significant differences between hemispheres were observed in mean flow velocities, except in the anterior cerebral arteries with right predominance. Flow velocities were higher in women and in the youngest age group. No significant differences in the pulsatility indices were found between sexes or between age groups. The flow velocities in this series are lower than those reported for other series. ConclusionsThe hemodynamic parameters in this series are lower than in other series and are influenced by the altitude, age, and sex.

P: 27 Evaluation of Neurocognitive Function in Patients With Compensated and Decompensed Cirrhosis

BACKGROUND: Cirrhosis is the end result of chronic liver damage caused by multiple entities. Up to 20%–60% of patients with cirrhosis are affected by a peculiar type of mild cognitive impairment related to selective attention and executive functions, visuomotor capacity, psychomotor speed, inhibition of response and selection of response that can only be detected by psychometry. METHODS: An observational, cross-sectional, analytical study was carried out. A total sample of 126 patients was established, 64 patients for each group. The NeuroPsi instrument was applied to determine the domains (Orientation, Attention, Visual Episodic Memory, Verbal Episodic Memory, Language, Reading Writing, Executive Conceptual Functions and Executive Motor Functions); With the transcranial Doppler, the hemodynamic parameters such as velocity, pulsatility index, resistance index, as well as the apnea index to assess cerebral vasoreactivity were evaluated. RESULTS: Up to now, 55 patients were studied, two groups were established: compensated cirrhotic 18 and decompensated, the gender ratio was 38% men and 62% women, with a median of 60 years. Compensated cirrhotics showed a higher percentage of patients without hepatic encephalopathy (HE) 65% vs 27.1%. The mean Child Pugh score was 7.47 ± 1.82. MELD Na mean for total patients was 12.98 ± 5.04. Of the masters, Reading Writing with 4.50 ± 0.89 for compensated and 4.85 ± 0.50 in decompensated (P = 0.07); in the domain of Executive Motor Functions with 5.69 ± 1.8 for compensated and 6.24 ± 0.89 decompensated (P = 0.16). CONCLUSIONS: This study could not find significant differences in the averages obtained in the 8 cognitive domains explored, between the compensated and decompensated cirrhotic patients, nor correlation between the Child Pugh score and the performance in the cognitive tests; It is considered relevant to increase the sample of this study to have more solid evidence. In the cerebral hemodynamic parameters assessed by transcranial Doppler, there were no significant differences between compensated and decompensated patients.

Early cardiovascular function and associated hemodynamics in adults with isolated moderate-severe traumatic brain injury: A pilot study

BackgroundWhile cardiac dysfunction has been described following traumatic brain injury (TBI), its association with systemic and cerebral hemodynamics is not known. We examined the contemporaneous relationship between early cardiac function with systemic and cerebral hemodynamic parameters after moderate-severe TBI. MethodsBedside transthoracic echocardiography (TTE) and transcranial Doppler (TCD) ultrasonography were performed within 24 h in patients > 18 years with isolated moderate-severe TBI. Systemic hemodynamic parameters were quantified using routine monitoring [heart rate and mean arterial pressures (MAP)] and calculation from echocardiographic data [stroke volume index (SVI), cardiac index (CI), and systemic vascular resistance index (SVRI)]. Systolic dysfunction was defined using TTE as global longitudinal strain (GLS) > -16%. Mean middle cerebral artery velocity (FVm) was the measure of cerebral hemodynamics and quantified using TCD. ResultsAmong 15 patients [mean age 43 ± 13 years, GCS 5 ± 3, 73% male], 15 TTE and 15 TCD exams were performed simultaneously. Five (33%) patients had systolic dysfunction, with significantly worse GLS (median [IQR] −12.1% [−14.1, −12] vs. −19.1% [−19.9, −17.7], p = 0.004). Median (IQR) MAP was 97 (89, 107) mmHg, SVI (29.0 [20.5, 31.0] mL m−2), and CI (2.83 [2.05, 3.10] L/min m−2) were low to normal, while SVRI (2704 dyne sec/cm5 m−2 [2210, 4084]) was normal to high. None of the patients had abnormal TCDs. Higher GLS (reduced systolic function) was associated with lower SVI (r2 = 0.274, p = 0.03) but not other parameters. ConclusionSystemic hemodynamic parameters were consistent with an early catecholamine-excess state. While reduced systolic function was associated with lower SVI, there was no relationship with reduced cerebral perfusion, possibly due to normal MAP.

Cerebral hemodynamic abnormalities of patients with ischemic stroke who are opium addicted: A study by transcranial doppler ultrasonography

Background: Ischemic stroke as the major cause of mortality and morbidity worldwide has different risk factors. One of its modifiable risk factors is opium addiction whose role is not clear yet. This study aimed at assessing the hemodynamic parameters in ischemic stroke patients addicted to opium using transcranial Doppler (TCD) ultrasonography and comparing them with non-addicted patients. Methods: This comparative cross-sectional study was conducted in an academic hospital in the north of Iran in 2016. All the patients diagnosed as ischemic stroke underwent cerebrovascular ultrasound in the first 4 days of symptoms onset. Frequency of hemodynamic abnormalities confirmed by pulsatility index (PI) and mean flow velocity (MFV) were determined and compared between the two groups. The data were analyzed by chi-square test, t-test, and multiple logistic regression models using SPSS software. Results: A total of 353 patients with ischemic stroke (92 addicted and 261 non-addicted patients) were enrolled in the study. Univariate analysis indicated that the PI and MFV differences were statistically significant between two groups of addicted and non-addicted patients (P = 0.0001). By multivariate logistic regression model, the age [odds ratio (OR) = 1.143], diabetes mellitus (DM) (OR = 3.875), hypertension (HTN) (OR = 2.557), and opium usage (OR = 9.615) had influence on PI and only opium usage (OR = 3.246) had influence on MFV. Conclusion: Opium usage affects the cerebral hemodynamic parameters and increases the chance of having abnormal PI as ten-fold and abnormal MFV as three-fold.

Optoacoustic Calcium Imaging of Deep Brain Activity in an Intracardially Perfused Mouse Brain Model

One main limitation of established neuroimaging methods is the inability to directly visualize large-scale neural dynamics in whole mammalian brains at subsecond speeds. Optoacoustic imaging has advanced in recent years to provide unique advantages for real-time deep-tissue observations, which have been exploited for three-dimensional imaging of both cerebral hemodynamic parameters and direct calcium activity in rodents. Due to a lack of suitable calcium indicators excitable in the near-infrared window, optoacoustic imaging of neuronal activity at deep-seated areas of the mammalian brain has been impeded by the strong absorption of blood in the visible range of the light spectrum. To overcome this, we have developed and validated an intracardially perfused mouse brain preparation labelled with genetically encoded calcium indicator GCaMP6f that closely resembles in vivo conditions. By overcoming the limitations of hemoglobin-based light absorption, this new technique was used to observe stimulus-evoked calcium dynamics in the brain at penetration depths and spatio-temporal resolution scales not attainable with existing neuroimaging techniques.

Parámetros hemodinámicos cerebrales, determinados mediante Doppler transcraneal, en un grupo de voluntarios sanos a 2.850 metros de altura

BackgroundTranscranial Doppler ultrasound (TDU) is useful in cerebrovascular patients. TDU findings are operator-dependent; they can also be influenced by anatomical and physiological variables as well as by the altitude at which the study is done. ObjectiveTo report the cerebral hemodynamic parameters measured by TDU in subjects who live in Quito, Ecuador (altitude 2850 meters). Material and methodsWe recruited 47 volunteers with no history or clinical evidence of stroke, hypertension, metabolic disorders, or hematologic disorders; 2 patients were excluded because they did not have a viable cranial window for TDU study. Thus, we recorded mean cerebral blood flow velocity, peak systolic flow velocity, end-diastolic flow velocity, and pulsatility indices in 45 patients (28 (62.2%) women; mean age, 35.9 years). We recorded patients’ age, sex, and hematocrit. We analyzed cerebrovascular hemodynamic parameters by sex and age group. ResultsNo significant differences between hemispheres were observed in mean flow velocities, except in the anterior cerebral arteries with right predominance. Flow velocities were higher in women and in the youngest age group. No significant differences in the pulsatility indices were found between sexes or between age groups. The flow velocities in this series are lower than those reported for other series. ConclusionsThe hemodynamic parameters in this series are lower than in other series and are influenced by the altitude, age, and sex.